Deregulation has presented businesses with new and complex issues with respect to purchasing and managing energy. Utility companies provide a bundle of services including generation, distribution, and transmission. Deregulation has unbundled these services and allowed consumers to chose among a multitude of competing electrical generation suppliers while the local company continues to handle the distribution and transmission of power directly to the consumer. Competition is advantageous for consumers in that they are able to purchase cheaper energy, however competition among generation suppliers produces differing and often-complex pricing schemes. Although time varying billing rates existed for industrial consumers prior to deregulation, the billing was quite straightforward. In particular, industrial consumers would simply pay a single bill per period, normally each month, according to their total energy usage (kW-hr). Today, however, billing is quite a bit more complicated for industrial consumers as well as for residential consumers. In addition to having to separately pay a generation supplier and a local distributor, energy prices vary with the time of use (e.g., weekday, weekend, day, night, hour-of-the-day). Stated differently and simply, energy consumption at peak times (i.e., high demand) costs consumers more than during non-peak hours (i.e., lower demand). On-peak versus off-peak billing enables energy suppliers to contract with consumers concerning the power that they will make available at certain times and the price charged. This allows consumers to make cost effective decisions relating the use of power and allows the utility companies to prevent brownouts or blackouts due to over consumption.
The competitive global economy as well as various energy conservation movements have forced companies to operate and conduct business in an ever increasingly efficient manner. Accordingly, businesses must determine when and how to operate in a more cost efficient way with respect to the use of energy. Unfortunately, the growth and ubiquity of electrical systems and machines makes energy management a large and increasingly complicated task. For instance, many industrial processes and machines are controlled and/or powered by electric systems. Such processes and machines include pumps providing fluid transport for chemical and other processes, fans, conveyor systems, compressors, gear boxes, motion control devices, screw pumps, and mixers, as well as hydraulic and pneumatic machines driven by motors. Such motors combine with other system components, such as valves, pumps, furnaces, heaters, chillers, conveyor rollers, fans, compressors, gearboxes, and the like, as well as with appropriate motor drives to form industrial machines and actuators. For example, an electric motor could be combined with a motor drive providing variable electrical power to the motor, as well as with a pump, whereby the motor rotates the pump shaft to create a controllable pumping system. Demand can therefore vary immensely depending on which machines are running and in the case of variable speed motors at what speed they are running (e.g., 30% of max 80% of max). Furthermore, electrical consumers, such as industrial facility operators in particular, normally have contracts with energy suppliers that specify a maximum amount of energy to be used per period of time and any amount of energy usage over that amount is penalized by charging an increased fee. Still furthermore, companies can set maximum usage levels at certain times to try and take advantage of contracted price schedules. Thus, there is a need for a system for controlling loads based on metered demand to ensure that energy demand does not exceed optimum limits in an operation.
Referring initially to FIG. 1 a conventional load control system 100 is depicted. System 100 includes a master controller 110, a plurality of switches 120 (Switch1 through switchN, where N is an integer greater than one) coupled to the master controller 110, and a multitude of loads 130 (Load1 through LoadX, where X is an integer greater than one) associated with each switch. Conventionally, loads are metered (not shown) and data is collected and transmitted to a central master controller 110. The master controller 110 subsequently sheds loads based on a preconfigured scheme priority if energy use is above a threshold level. However, predetermining a priority scheme to shed loads lacks the granularity and the intelligence necessary to take advantage of the pricing options offered by electrical generation suppliers as well as accounting for other priorities and constraints such as objectives or business goals in real time.